Chromatographic separation member and method

ABSTRACT

There is described a chromatographic separation member including a substrate carrying on at least one surface a thin layer of a chromatographically active capture material. Also described is a chromatographic separation method for separating a component of interest from a fluid utilizing the chromatographic separation member.

REFERENCE TO RELATED APPLICATIONS

This is a divisional application of prior application Ser. No.11/053,810, filed Feb. 9, 2005 by Kolesinski et al., entitledCHROMATOGRATOPHIC SEPARATION MEMBER AND METHOD and which claims thebenefit of provisional application Ser. No. 60/600,139, filed Aug.10,2004.

This application relates to a chromatographic separation memberincluding a substrate carrying on at least one surface a thin layer of achromatographically active capture material and to a method forseparating, or removing, one or more components from a fluid which maycontain a mixture of components utilizing the chromatographic separationmember.

BACKGROUND OF THE INVENTION

The continuing surge in the development of biotechnology products, e.g.,therapeutic proteins and industrial bioproducts such as organic acids,has created a requirement for new and economically viable separation andpurification methods and apparatus. Biochemical technologies use enzymesor microorganisms to convert feedstock to the desired products, e.g.,fermentation products. In some processes, such as those practiced in aseparator reactor, removal of the product from the reaction vesselduring the production process will increase the product yield byreducing the concentration of the self terminating material. In otherprocesses it may be desirable to remove by-products and contaminants toimprove efficiency and yield.

It may also be desirable to remove a product from a reaction vessel inits pure form, thus eliminating further conversion of the product intosome other form, such as the formation of the salt of an organic acid.The conversion process normally generates waste streams that have to bedisposed of in an environmentally sensitive manner.

Methods for performing fluid/fluid separations using a continuous websystem have been disclosed previously. Several approaches have beentaught using continuous webs packed with sorbent particles, coated withsorbent materials or sorbent fibers. Generally, these methods followsimilar procedures wherein the web is passed through a solutioncontaining the target molecules and the web then enters a de-sorptiontank where the product is collected.

These approaches have not have not provided completely satisfactoryresults. For example, U.S. Pat. No. 5,256,298 reports that poorperformance results when chemically interactive porous particulatematerials are used. The '298 patent gives a brief description of thediffusion limitation of porous materials. Thus, web separation systemsemploying sorbent particulate materials have not provided the desiredresults.

Another area of great interest is that of water remediation processes toremove contaminants from and purify water and processes for theremediation of contaminated soil. Processes which utilize granulatedactivated carbon are known for water and soil remediation.

As the state of the art moves forward, efforts continue to developimproved and more efficient separation processes and materials for theremoval of target molecules from fluids such as in water remediationprocesses, the removal of contaminants from soil and for the recovery oftarget molecules in the preparation of biotechnical and other products.

BRIEF SUMMARY OF THE INVENTION

According to one aspect of the invention there is provided achromatographic web separation method which may be implemented withseparation processes carried out with fluids such as water or fluids inbioreactors or other chemical processes to separate one or more desiredcomponents from fluids such as fermentation broths or other biomassmixtures. Generally, a fluid containing one or more target molecules isbrought into contact with a chromatographic separation web, which iscoated on one or both sides with direct capture or otherchromatographically active functional material, to remove the desiredtarget molecule(s) from the fluid. The fluid can be brought into contactwith the chromatographic separation web by various methods includingpassing the web through the fluid or applying the fluid to the web suchas by spraying or other fluid coating techniques , e.g., slot headcoating techniques.

The fluid may be any from which it is desired to separate, or remove,one or more components. The fluid may be water containing one or morecontaminants, a slurry of a solid in a fluid such as a slurry of soil inwater, a fluid containing a mixture of biological products prepared in abioreactor such as a fermentation broth, or a biomass mixture or a fluidcontaining other product mixtures prepared by other chemical processes.Where the fluid is a slurry such as of soil in water or a mixture ofmaterials in a fluid, the soil or mixture of materials can be maintainedin suspension with a mixer located in the fluid.

The chromatographic separation web can be a continuous web which canthen be passed through a product de-sorption tank where the capturedmaterial is removed from the web and collected and the method repeated.Alternatively, the web may be taken up on a rewind roll and stored fortreatment at a subsequent time to collect the captured material.

In one embodiment where a continuous web is utilized, after the capturedmaterial is removed and collected in a product de-sorption tank, the webis passed through a wash tank and an equilibration tank before beingpassed through the reactor or other product-containing vessel to beginthe cycle again. In another embodiment the web may be unwound from aroll and after passing through the product-containing vessel, passedthrough a product collection vessel where the captured product isremoved and collected and the web then wound onto a rewind roll.Alternatively, the web containing the captured product material may berewound directly onto the rewind roll and stored for later treatment andremoval of the product.

In another aspect of the invention there is provided a chromatographicseparation web which includes a substrate carrying on one or both sidesa thin continuous layer of a capture material. Any capture chemistry canbe used to separate the desired product(s) from the mixture. The web maybe chemically modified using various interactive functional chemistriessuch as by depositing a coating of the capture material on the substrateor by direct reaction of the capture material with the substrate.

The capture material is a thin layer of a functionalized polymericmaterial which is chemically interactive with the desired product. Thefunctionalized polymeric material includes a moiety which exhibits ahigh affinity and specificity for the product of interest. Thefunctionalized polymeric material is “targeted”, i.e., it specificallyand efficiently interacts with and binds to the desired product. Thebinding between the desired product and the functionalized polymericmaterial may be covalent or non-covalent (e.g., hydrophobicinteractions, electrostatic interactions, dipole interactions, van derWaals interactions, hydrogen bonding, etc.). Most often the binding isnon-covalent.

Employing the chromatographic web, or belt, direct capture method of theinvention, both for in situ and post-reaction product capture, willimprove the production of bioproducts, reduce the cost of these productsand provide environmentally improved processes. The direct capture,moving web separation method will simplify the capture of products frombiomass containing extraneous matter without concern of fouling thecapture support. Products obtained from plants, trees or fermentationbroths may be captured without having to eliminate the debris normallyassociated with these processes. The direct capture, moving web methodwill also find utility in applications such as remediation processesincluding water and soil remediation processes. An example is thecapture of metals or other components from industrial waste streams orremediating contaminated soil. The continuous moving web will be veryefficient in capturing products from very dilute solutions. The sorptionand de-sorption rates are generally surface related and are fast therebyproviding fast and efficient separation methods.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the invention as well as other objects andadvantages and further features thereof, reference is made to thefollowing detailed description of various preferred embodiments thereoftaken in conjunction with the accompanying drawings wherein:

FIG. 1 is a partially schematic side sectional view of one embodiment ofa chromatographic separation member according to the invention;

FIG. 2 is a partially schematic side sectional view of one embodiment ofa chromatographic web separation method according to the invention;

FIG. 3 is a partially schematic side view of another embodiment of achromatographic web separation method according to the invention; and

FIG. 4 is a partially schematic side view of another embodiment of achromatographic web separation method according to the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

As described previously, the chromatographic web separation methodemploys a chromatographic separation member, which may be in the form ofa web, or belt, which has a substrate carrying on one or both sidesthereof a capture material functionalized with specific capturechemistries. The present separation method may employ a continuousrecycyling configuration for the web. In another embodiment there areutilized web unwind and rewind rolls. In this embodiment the webmaterial is pulled from the unwind roll by a drive mechanism on therewind roll with the web passing through a container or containersholding mixtures containing target materials. The web containing thecaptured compounds may be subjected to drying conditions, if desired,and taken up on the rewind roll and stored for subsequent treatment ofthe web material at a later time.

The chromatographic separation member includes a substrate which hasadhered to one or both surfaces a thin layer of a capture material. Thelayer of capture material may be a substantially uniform continuouslayer or a patterned layer.

Referring now to FIG. 1 there is seen a chromatographic separationmember 10 according to the invention. The member 10, which is preferablyin the form of a web. or belt, includes a substrate, or support, 12 anda thin layer 14, e.g., from about 0.25μ to about 3.0μ thick, of afunctionalized polymeric material. The substrate 12 may be of anysuitable material including naturally-occurring and synthetic materials.Typical suitable materials include synthetic organic materials, metallicmaterials, fibrous materials such as non-woven and woven fibers,membrane structures and any material capable of being formed into a selfsupported web, or sheet. Examples of useful synthetic polymericmaterials are polyesters, cellulosics, polyamides, polyolefins,polyvinyl polymers, etc. Metal films such as aluminum may be employed.Films of metallized plastics are also useful. Many types of woven andnon-woven fabrics would find utility as suitable belt/web materials aswould other membrane structures.

The substrate 12 may be of any thickness which is sufficient to providethe mechanical strength such that the web can perform its functionaccording to the invention. The substrate may also be subcoated with asuitable material to enhance adhesion of the capture material to thesurface of the substrate. A layer of a hydrophilic polymer such asgelatin may be coated on the surface of the substrate for this purpose.

The chemical functionalization of the belt/web materials, can be bycoating and immobilizing functional polymers and/or functional monomersonto the surface(s) of the supports. Coating can be accomplished bytechniques known to those skilled in the art. The web substrate may becoated using a slot head coater or by dip coating, gravure roll, reverseroll or other coating methods. The preferred coating method in anyparticular instance will be dependent primarily on the type of supportand material and application. In some instances, direct chemicalreaction with the support material may be the preferred technique tochemically modify the belt/web support material with the capturematerial. For example, where an organic polymeric material is used asthe substrate, it may be preferable to employ direct chemicalmodification of the substrate by reaction of the substrate material witha functional monomeric or polymeric material.

The capture material is preferably cross-linked to the substrate tomaintain its adherence to the substrate. Di- or multifunctional reagentsmay be used to chemically cross-link the polymeric material.

The chemical modification of the belt/web supports is generallyaccomplished by coating and immobilizing functional polymers and/ormonomers onto the surface(s) of the substrate. Co-polymers containingmonomers that provide chemical functionality and monomers thatcontribute to the immobilization of the polymer film, are coated ontothe surface of the belt/web supports. Immobilization may be accomplishedby various methods, preferably by thermal or photo-chemical mechanisms.RF plasma polymerization may be utilized to functionalize the surface ofthe substrate material.

Techniques for the coating, cross-linking and immobilization offunctionalized polymeric films are well known to those skilled in theart and are described, for example, in the micro-lithography technologyliterature which finds applications in the graphic arts, printed circuitboard, integrated circuit and chromatography/separation areas.

The casting of solutions and mixtures of functional monomers forsubsequent polymerization and cross-linking has been demonstrated in thepreparation of electrophoretic and chromatographic media. Directreaction to functionalize a substrate material can be accomplished bythose skilled in the art by employing well known chemical reactions toattach appropriate ligands to the substrate material. Graftingtechniques can also be used.

As mentioned above, the chromatographically active, functional polymerlayer 14 is preferably from about 0.25μ to about 3.0μ in thickness.However, it will be recognized that the thickness of the functionalpolymer layer may be less or greater in appropriate instances.

One advantage of the direct reaction of the capture material with thesubstrate is the avoidance of any potential adhesive or cohesive failureof the functional material film on the substrate. However, there areknown chemical reactions that produce highly reactive species, e.g.,nitrenes and other free radicals by photo-chemical or thermal activationwhich can be exploited to bind the functional polymeric film to thesubstrate material thereby substantially reducing or minimizing thepossibility of adhesive or cohesive failure.

Examples of chemical modification include ion exchange chemistries(IEX), affinity, immobilized metal affinity chromatography (IMAC),chiral phases, hydrophobic interaction (HIC) reverse phase (RP), lowercritical solution polymers (LCST), metal chelating polymers, andmagnetic phases and Molecular Recognition Imaging.

Typical suitable functional polymeric capture materials includepolybutadiene for reverse phase interactions. Functional polymer capturematerials which undergo ion exchange interactions are preferred.Preferred functional capture materials are copolymers of pyridiniumylide with cation and anion exchange monomers such as sulfopropylmethacrylate, potassium salt, and p-vinylbenzylammonium chloride. Thepyridine ylide monomer, under photochemical or thermal conditions,generates a reactive species. For techniques for irradiating polymerscontaining pyridinium ylide moieties see U.S. Pat. No. 4,670,528. Forchromatographic separation techniques utilizing N-acyl diazepinepolymers containing pyridinium ylide moieties see U.S. Pat. No.5,159,039.

Another advantage of the chromatographic web separation method is thatthe thickness of the functional capture film on the web support may beadjusted to increase or decrease the amount of capture as desired. Thus,for example, the ligand densities of ion exchange chemistries can bemodified as required thereby improving the capture efficiency ofspecific molecules in the mixture. Given the same surface area, it hasbeen shown that when the thickness of a polymer film containingion-exchange moieties is increased the amount of target moleculescaptured is increased.

The chromatographic separation method of the invention may be carriedout with a stand alone apparatus or be incorporated as an integral partof any type of reactor for removal of products during the reactionprocess.

The broad based utility of the chromatographic separation method willfind many diverse applications both in laboratory and industrialenvironments, including in the separation and collection of the desiredcompound in the synthesis of chemical compounds, the separation andpurification of biochemical products from mixtures such as fermentationproducts and in water and soil remediation processes.

The apparatus by which the chromatographic separation method is carriedout may include several product de-sorption tanks or other methods canbe utilized to desorb the products from the web. The method thus allowsfor the separation of various products which were captured by thechromatographically active functional polymer film on the web as itpasses through the product mixture. In addition to traversing the webthrough several product de-sorption tanks, the captured product can beremoved at washing stations where the web can be contacted with amolecule-specific interactive de-sorption fluid, such as by spraying thefluid onto the web, to release the target product for collection.

A step gradient technique can be used to separate and purifymulti-component mixtures using standard chromatographic column formats.An example would be the separation and purification of a protein mixturethat has been injected on a chromatography column, by using a stepgradient of solvent or buffers. If an ion exchange method is employedfor separation of products using a step gradient, as the conductivity ofthe system is increased in a step wise manner, the ionic interaction ofproduct with the ion exchange surface is effected with the subsequentrelease of said product at that particular ionic conductivity, into theflowing buffer, leaving the more strongly interactive product speciesbound to the capture surface, only to be released as the conductivity ofthe system is further increased.

The step gradient technique can be employed very effectively with themoving web separation method of the invention. In a continuous recyclingmode, the captured products will be separated and purified from theproduct-containing vessel, until the desired products of the reactionvessel are substantially completely separated and collected inde-sorption vessels, each containing specific concentrations (such asincreasing conductivity, pH. etc.) of de-sorption buffers or solventmixtures. The advantageous separation method of the invention wouldreplace the arduous task of repeated injections onto a chromatographycolumn to separate the mixture components.

It can be seen that the chromatographic separation method of theinvention is a continuous method in contrast to the batch type methodnormally associated with chromatography column separations. Thechromatographic separation method is particularly useful in the captureof desired products from dilute solutions or dispersions.

In another embodiment of the invention the capture material is appliedto the web support in a patterned manner, e.g., by gravure coatingtechniques, such as in the form of lines, dots or other patterns.Providing the film of capture material in a patterned arrangementsignificantly increases the total surface area of the capture materialwhich is available to interact with the desired product to be separatedfrom the mixture of components. The patterned layer of capture materialis a continuous layer with thickness variations in accordance with theparticular pattern.

Where the layer of capture is provided in a patterned arrangement it ispreferred to initially deposit a thin, substantially uniformly-thicklayer of the capture material followed by depositing a patterned layerof the material thus forming an overall continuous patterned layer.

Such patterns, e.g., lines or dots., may be on the order of nano- ormicro-sizes or larger. The preferred size will be primarily dependentupon the mechanism of formation of the patterned or imaged coating andrequirements. For example, if it is desired to generate a molecularimage the resolution requirements far exceed those necessary to producelines or dots to increase surface area.

The continuous patterned capture film can be formed directly on the websupports by specific coating techniques. Alternatively, a substantiallyuniform layer of the capture material can be deposited on the supportand then imaged using digital, electron beam, ultraviolet light or otherphotochemical methods in accordance with the desired pattern. Theunexposed area of the capture film can then be removed leaving behind awell defined image.

An example of the use of a pattern of the capture material on theseparation member support is where molecular recognition is theinteractive mechanism to capture the target molecules.

The chromatographic separation member can be reused or discarded andreplaced after each use in which case cleaning in place procedures canbe eliminated. The particular embodiment selected in any specificinstance may be dictated by economic considerations.

The method of the invention will now be described with respect to theembodiment thereof wherein the separation web is passed through a fluid.Referring now to FIG. 2 there is seen an endless recirculating,chromatographically interactive web 20 which includes a support havingadhered to one or both surfaces thereof a thin film of a capturematerial. The web 20, which may be of any of the support and capturematerials described previously, travels in the direction illustrated bythe arrow and enters a vessel, or container, 22 such as a bioreactorcontaining a mixture of components in a fluid 24, through an opening 26in the vessel. As shown, the web is passed through the fluid supportedby a series of idler, or tension rollers 28. It will be apparent thatthe web drive and tracking mechanism may use tension rollers, sprocketfeed devices or any other useful web drive elements to drive and trackthe web. Many such devices are known in the art.

The web 20 may be wound around any number of rollers 28 in vessel 22,that is, any desired length of web 20 may be present in the container atany time. The rate of travel of the web in vessel 22 can be adjusted asdesired. The web 20 may be of any desired width and any desired overalllength. As described above, the desired component, or product, in thefluid 24 is captured by the functional material on the surface of theweb.

The web 20 carrying the desired component, or product, exits from vessel22 through an opening 30 and enters a product de-sorption tank 32 wherethe web is guided by a series of idler, or tension, rollers 34. Thecaptured product is desorbed from the surface(s) of web 20 andsubsequently removed from tank 32 and collected. The captured product isdesorbed from the web by any of the de-sorption techniques previouslydescribed.

As described above with respect to the product-containing vessel 22, theweb 20 may be wound around any number of rollers 34 in de-sorption tank32 and any desired length of web 20 may be present in the de-sorptiontank at any time. The rate of travel of the web in de-sorption tank 32can be adjusted as desired. Further, although one de-sorption tank isshown in FIG. 1, it will be understood that the web 20 may be passedthrough any number of de-sorption tanks as necessary to remove andcollect the desired product separated from the fluid mixture by web 20.

The web 20 then is passed through a wash tank 40 and equilibration tank42 before being re-circulated through vessel 22 to begin the separationcycle again. Any number of separation cycles may be carried out in orderto recover the desired amount of product from the product-containingvessel 22.

Referring now to FIG. 3 there is illustrated another embodiment of theinvention wherein a web 50, which travels in the direction of the arrow,is passed through a plurality of vessels 52-60. In this embodimentvessel 52 is a reaction vessel, vessel 54 is a product collection vesseland vessels 56, 58 and 60 are wash and equilibration vessels. Vessels52-60 also can include means for conveniently emptying the vessels suchas stopcocks 62.

In another embodiment of the method of the invention, the fluid mixtureis applied to the chromatographic separation member by such as byspraying the mixture thereon or by applying the fluid to the separationmember by other fluid coating techniques including slot head coatingprocesses. The sequence of steps following the application of the fluidto the separation member is generally the same as those described above,for example passing the separation member through a de-sorption vesselto remove and collect the target molecule and an equilibration vessel.

An advantage of applying the fluid to the surface of the separationmember is that the path of the target molecule to the surface of thecapture material is minimized and there is more immediate contact of thetarget molecule with the surface of the capture material.

According to a preferred embodiment of the fluid application aspect ofthe invention, which will be described with respect to FIG. 4, the fluidis applied to the separation member 50 when the separation member is incontainer 70, preferably at a point where the member is traveling in theupward direction, e.g., at point 72. The fluid is propelled through tube74 by pump 76 and is applied to the surface of the separation member bymeans of spray heads 78. According to this embodiment, the fluidcontinuously comes into contact with capture material as the membertravels through the vessel. Fluid from which sufficient targetmolecules, such as contaminants in water, can be removed from thecontainer 70 by stopcock 62. Although the separation member has beenshown as being wound around one idler roller in container 70, it will beunderstood that the web 50 may be wound around any number of rollers invessel 70, that is, any desired length of web 50 may be present in thecontainer at any time as has been described with respect to theembodiments illustrated in FIGS. 2 and 3. The web 50 can then besubjected to any of the sequence of steps described above includingcollection of the target molecule, washing, equilibration, etc.

The separation members and methods of the invention can beadvantageously utilized for water and soil remediation to removecontaminants such as creosote, polycyclic aromatic hydrocarbons (PAH),polychlorinated biphenyls (PCB) or other molecules.

EXAMPLES

The invention will now be described further in detail with respect tospecific preferred embodiments by way of examples, it being understoodthat these are intended to be illustrative only and not limiting of thescope of the invention. Various changes and modifications to thedisclosed embodiments will be apparent to those skilled in the art. Suchchanges and modifications, including without limitation, those relatingto the materials, process parameters and/or methods of the invention maybe made without departing from the spirit of the invention and the scopeof the appended claims. All parts and percentages recited are by weightunless otherwise specified.

Example I

A chromatographic separation member according to the invention wasprepared by coating, with a slot-head coating apparatus, anapproximately 1μ thick layer of a strong cation exchange (SCIEX)copolymeric capture material on the gelatin-coated surface of asubcoated Mylar© (polyethylene terephthalate) film. The SCIEXcopolymeric capture material was prepared by copolymerizing 2 parts of apyridinium ylide monomer (shown at column 13, lines 60-65 of U.S. Pat.No. 4,670,528) and 8 parts sulfopropyl methacrylate, potassium salt(available from Aldrich Chemical Co.)according to the polymerizationtechniques described in the '528 patent.

A sample of the separation member, an approximately 1½” by 3½” sectionof the separation member, was then exposed for about 20 minutes to a 5.5watt, 2⅛” long, UV lamp, available from Ace Glass Co., New Jersey (PartNo. 90-0012-01) to cross-link the polymer.

Subsequently, the sample of the separation member was washed with asolution of 20 millimolar (mM) potassium di-hydrogen phosphate (KH₂PO₄)(“buffer A”) two times in a crystallizing dish.

A protein solution was prepared by dissolving cytochrome C (17 mg) andlysozyme (17 mg) in buffer A (40 mL).

The protein solution (10 mL) was added to the sample having the SCIEXcapture material in a crystallizing dish to cover the sample. The samplewas swirled in the protein solution for about 3 minutes. The proteinsolution was then decanted from the dish and the sample washed two timeswith buffer A (20 mL) to remove any extraneous material.

The sample was then swirled in 10 mL of a solution of buffer A (60%) andbuffer B (20 mM KH₂PO₄/0.5 molar sodium chloride). The resultingsolution was analyzed by high performance liquid chromatography (HPLC)at 280 nm. HPLC analysis showed that only one component of the lysozymeand cytochrome C components was removed by the above-described buffermixture.

The sample was then inserted into buffer B (10 mL) for about one minuteand the sample removed and analyzed by HPLC at 280 nm. HPLC analysisshowed that only the other of the cytochrome C and lysozyme componentswas removed from the separation member with buffer B.

The results show the capture by the chromatographic separation web ofthe desired proteins from solution and the ability to release andrecover the captured proteins from the member discriminately.

Example II

This example illustrates the capture and release of target molecules byreverse phase materials according to the invention.

A solution of 4-(vinyloxy)butyl stearate (0.5 g) in methylene chloride(15 mL) was prepared. An approximately 15×80 mm piece of double sidedMylar (Transilwrap LJ112, commercially available from Transilwrap Co.,Bethlehem, Pa.) was dipped into the solution for about 10 seconds andthen slowly withdrawn and dried with a flow of warm air.

The film was washed with acetonitrile and then with methanol and thendried as described above.

This capture member according to the invention, coated with a reversephase capture material, was then utilized in a number of extractions oftarget molecules from aqueous mixtures according to the followingprocedure:

The reverse phase-coated chromatographic separation member was immersedin a solution or mixture containing target molecules in a test tube fora few minutes. The member was then removed from the solution or mixtureand washed several times with water.

The member was then placed in a test tube containing˜1 mL acetonitrileto desorb any captured molecule. Subsequent HPLC evaluation @ 210 nm ofthe acetonitrile solution demonstrated whether capture and release ofthe target molecule had occurred. The capture or lack of capture isindicative of the hydrphobicity of the reverse phase-coated member andthe target molecule. The appropriate HPLC controls and blanks were run.

The following results of extraction performance by the reversephase-coated separation member were obtained Target Material Resultcaprolactam captured and released (from waste stream) oleic acidcaptured and released butyric acid not captured maleic acid not captured

These results show that the chromatographic separation members andmethod of the invention can be adapted to capture target moleculesselectively based on the hydrophobicity of the capture material and thetarget molecule.

Example III

This example illustrates the capture and release of target molecules bystrong anion exchange (SAIEX) materials according to the invention.

A strong anion exchange copolymer was prepared by copolymerizing 2 partsof the monomer described in Example I and 8 parts m-isopropyl-{acuteover (α)}, {acute over (α)}, dimethylbenzyl isocyanate (available fromAmerican Cyanamid). The copolymer (at approximately a 1% concentration)was dissolved in water containing a very small amount of Triton X-100, asurfactant available from (Baker Analyzed®).

A 1×2″ piece of Mylar film, coated on one side with gelatin, was dippedin the polymer solution for about 10 seconds, slowly withdrawn and driedwith a flow of warm air. The dried polymeric capture layer was thencross-linked by exposure to ultraviolet light by the procedure describedin Example I for ten minutes to crosslink the capture material.Subsequently the member was washed with water and dried.

A sample solution was prepared by dissolving maleic acid (1 g) in bufferA (20 mL), adjusted to pH 8.0 with NaHCO₃.

The separation film was dipped in the maleic acid solution for a fewseconds, removed and washed with buffer A solution two times to removeany extraneous material. The separation member was then extracted withbuffer B (1 mL) to desorb the target molecule.

The resulting solution was evaluated by HPLC @ 210 nm. The HPLC analysisshowed capture of maleic acid by the separation member and subsequentrelease therefrom in the extraction with buffer A.

Although the invention has been described in detail with respect tovarious preferred embodiments, it will be understood that these areintended to be illustrative only and the invention is not limitedthereto, but rather that those skilled in the art will recognize thatvariations and modifications may be made therein which are within thespirit of the invention and the scope of the appended claims.

1. A chromatographically active separation member comprising a) asubstrate having first and second opposed surfaces; and b) a drycontinuous film of a chromatographically active functional polymericmaterial carried by said first surface.
 2. The chromatographicallyactive separation member as defined in claim 1 wherein said continuousfilm has a substantially uniform thickness.
 3. The chromatographicallyactive separation member as defined in claim 1 wherein said continuousfilm has a thickness of from about 0.25μ to about 3.0μ
 4. Thechromatographically active separation member as defined in claim 1wherein said continuous film has a substantially non-uniform thicknessand is arranged in a pattern.
 5. The chromatographically activeseparation member as defined in claim 1 and further including acontinuous film of a chromatographically active functional polymericmaterial carried by said second surface
 6. The chromatographicallyactive separation member as defined in claim 5 wherein saidchromatographically active functional polymeric material carried by saidfirst surface and by said second surface are the same.
 7. Thechromatographically active separation member as defined in claim 1wherein said separation member further includes a layer of a hydrophilicpolymer adhered to said first surface of said substrate and wherein saidcontinuous film of chromatographically active functional polymericmaterial is deposited on said hydrophilic polymer layer.
 8. Thechromatographically active separation member as defined in claim 1wherein said chromatographically active functional polymeric material iscross-linked to said substrate.
 9. The chromatographically activeseparation member as defined in claim 7 wherein said chromatographicallyactive functional polymeric material is cross-linked to said substrate.10-18. (canceled)
 19. The separation member as defined in claim 1wherein said member comprises a continuous endless web.